摘要
反枝苋提取物能够显著增强小麦植株的抗高温胁迫能力,但其中起作用的活性成分尚不清楚.本研究采用生物活性追踪法,从反枝苋根部分离到5个化合物,经核磁共振波谱及质谱分析分别被鉴定为对羟基苯甲酸(1)、14-羟基肉豆蔻酸(2)、对甲氧基苯甲酸(3)、3-(羟乙酰基)吲哚(4)和3-吲哚甲醛(5).对羟基苯甲酸、对甲氧基苯甲酸和14-羟基肉豆蔻酸均能增强小麦对高温胁迫的耐受性,其中对甲氧基苯甲酸效果最突出,在100 μg/mL剂量下,与空白对照相比,小麦植株鲜重增加了 56.44％,茎叶长度增加了 30.03％,根长增加了 38.71％.经50 μg/mL对甲氧基苯甲酸处理小麦幼苗后,分别于40 ℃高温胁迫1、3、5和7 d,取样测定植株体内相关生理生化指标的变化.结果表明:高温胁迫1、3、5、7d后,与空白对照相比,小麦植株体内丙二醛含量分别降低了 32.59％、50.27％、57.53％、33.64％;脯氨酸含量在1、3和5 d分别增加了 28.57％、50.00％、29.87％,第7天降低了 5.16％;可溶性糖含量分别增加了39.76％、35.93％、41.33％、12.50％;超氧化物岐化酶活性分别增加了 39.48％、41.63％、26.09％、25.27％,过氧化物酶活性分别增加了 11.19％、32.05％、32.54％和26.90％,过氧化氢酶活性分别增加了 35.62％、50.97％、22.82％和25.89％.综上,对甲氧基苯甲酸可显著提高小麦抗高温胁迫的能力.
Abstract
Previous studies showed that the extract of Amaranthus retrofllexus could significantly enhance the heat stress resistance of wheat seedlings,but the active components responsible for this activity are still unknown.In this study,five compounds were isolated from the roots of A.retroflexus by using a bioassay-guided method.They were identified as p-hydroxybenzoic acid(1),14-hydroxymyristic acid(2),p-methoxybenzoic acid(3),3-hydroxyacetyl-indole(4),and 3-indole formaldehyde(5)by nuclear magnetic resonance spectroscopy and mass spectrometry analysis.p-Hydroxybenzoic acid,p-methoxybenzoic acid,and 14-hydroxymyristic acid could enhance the tolerance of wheat seedlings to heat stress with p-methoxybenzoic acid showing the highest activity.Under high-temperature stress,the fresh weight and length of aboveground,and root length of the wheat seedlings treated with 100 μg/mL p-methoxybenzoic acid increased by 56.44％,30.03％,and 38.71％compared with the control.The changes in relevant physiological and biochemical indicators were determined in wheat seedlings treated with 50 μg/mL p-methoxybenzoic acid and subjected to high-temperature stress for 1,3,5,and 7 days.The results showed that the malondialdehyde content in the plant decreased by 32.59％,50.27％,57.53％,and 33.64％compared with the control,respectively.The proline content increased by 28.57％,50.00％,and 29.87％on days 1,3,and 5,respectively,and then decreased by 5.16％on day 7.The soluble sugar content increased by 39.76％,35.93％,41.33％,and 12.50％.Superoxide dismutase enzyme activity increased by 39.48％,41.63％,26.09％and 25.27％.Peroxidase enzyme activity increased by 11.19％,32.05％,32.54％,and 26.90％.Catalase enzyme activity increased by 35.62％,50.97％,22.82％,and 25.89％,respectively.Collectively,p-methoxybenzoic acid can significantly improve wheat resistance to high-temperature stress.
维普
万方数据